IgG Human
Human serum.
Ig gamma-2A chain C region, A allele, Immunoglobulin heavy chain gamma polypeptide, Ighg, Igh-1, Igh-1a, 1810060O09Rik.
Sterile Filtered White lyophilized (freeze-dried) powder.
Greater than 96.0%.
Description
Human IgG protein produced in Human plasma having a molecular mass of 150kDa.
Product Specs
Ig gamma-2A chain C region, A allele, Immunoglobulin heavy chain gamma polypeptide, Ighg, Igh-1, Igh-1a, 1810060O09Rik.
Human serum.
Product Science Overview
IgG is a large glycoprotein with a molecular weight of approximately 150 kDa. It exists in a monomeric configuration, meaning it is composed of a single unit. The IgG molecule consists of four polypeptide chains: two identical heavy chains (gamma chains) and two identical light chains (either kappa or lambda chains) . These chains are linked together by disulfide bonds, forming a Y-shaped structure. The variable regions of the heavy and light chains confer antigen-binding specificity to the antibody .
There are four subclasses of IgG in humans: IgG1, IgG2, IgG3, and IgG4. These subclasses differ in their amino acid sequences and disulfide bonding, which result in variations in their physical properties and effector functions . IgG1 is the most abundant subclass, followed by IgG2, IgG3, and IgG4.
IgG antibodies are major components of humoral immunity, which is the aspect of immunity that is mediated by macromolecules found in extracellular fluids. IgG plays several critical roles in the immune response:
- Pathogen Neutralization: IgG binds to pathogens such as viruses, bacteria, and fungi, neutralizing their ability to infect cells .
- Opsonization: IgG coats the surface of pathogens, marking them for recognition and ingestion by phagocytic immune cells .
- Complement Activation: IgG activates the classical pathway of the complement system, a cascade of immune protein production that results in the elimination of pathogens .
- Antibody-Dependent Cellular Cytotoxicity (ADCC): IgG binds to infected cells and recruits natural killer (NK) cells to destroy the infected cells .
- Toxin Neutralization: IgG binds and neutralizes toxins produced by pathogens .
IgG is the only antibody isotype that can cross the placenta, providing passive immunity to the fetus during pregnancy . This maternal IgG protects the newborn until its own immune system becomes fully functional. Additionally, IgG is present in colostrum, the first form of milk produced by the mammary glands, which provides further immune protection to the neonate .
In clinical settings, IgG levels are often measured to assess immune function. Abnormal levels of IgG can indicate various health conditions, including immunodeficiencies, chronic infections, and autoimmune diseases .
